The invention relates to an airbag system for a motor vehicle.
EP 0 728 628 A2 discloses an airbag system, which has a generator housing with walls for a blast channel of an airbag. A front wall of the blast channel is formed by two single walls, which are detachably connected and can be separated from each other in the event of a head impact or a load.
An object of the invention is to provide an improved airbag system for a motor vehicle that allows simple installation in the vehicle and an unimpeded and guided lowering of a channel wall of the blast channel in the event of a head impact or a load.
The object is achieved with the embodiments of the invention described and claimed hereinafter.
One of the advantages of the invention is that owing to the use of a head impact element, which can be pivoted on the generator housing, it can be immediately lowered and swiveled without hindrance in the event of a load. Thus, injuries to the head of a motor vehicle occupant are largely avoided. To this end, in a first channel wall of the generator housing, which is aligned in relation to the motor vehicle occupant, a head impact element can be swiveled unilaterally in bearings. In a second channel wall of the housing, located below, the head impact element can be suspended in a starting position by a compression connection and can be unfastened in the event of a load.
The head impact element comprises a U-shaped bow with legs, which are mounted on the first channel wall of the housing and are connected by a web element. The web element forms an additional upper channel wall, which includes, as the connection, a receiving flute for engaging a molded on hook-shaped bar on the second channel wall of the housing. The bow can react directly in the event of a head impact. Delays caused, for example, by a deformation, are avoided.
The connection between the head impact element and the second channel wall of the generator housing can be designed as a form-fit connection. For example, the second channel wall of the housing may have a hook-shaped bar, the receiving flute of the head impact element may have a configuration that matches the configuration of the hook-shaped bar.
Furthermore, a raised retaining crease of the head impact element is also conceivable according to the invention. The retaining crease is held form-fittingly against an impressed receiving crease in the second channel wall of the generator housing The cross section of the receiving crease is approximately W-shaped with two stop creases. An upper edge of the wall of the generator housing is bent outwardly. Corresponding with the receiving crease, the retaining crease of the upper channel wall is held clampingly against the receiving crease.
Furthermore, at least one elastic spring element is also possible according to the invention. The spring may be disposed between the head impact element and the wall of the generator housing and is compressed in the event of a head impact. The wall of the head impact element can be lowered in the event of a load.
In an embodiment of the invention, in the event of a head impact the upper channel wall of the head impact element can be swung about an approximately horizontal swivel axis in relation to the stationary second channel wall of the generator housing. In the event of a load it can be swung in the downward direction, thus undoing the form-fit connection. In this way, the head of a motor vehicle occupant does not strike a stationary edge of a blast channel wall, but rather this hard edge moves or swings in the event of a load to reduce the impact. Furthermore, the impact is also decreased by disconnecting the connection between the head impact element and the wall of the generator housing.
The generator housing is held on the face-sided brackets by fasteners, which are connected rigidly to a carrier of the motor vehicle body by bolted angle brackets. The connection to the carrier is relatively inflexible, so that all loads, like vibrations, are absorbed during the blast and there is no deformation upon head impact.
Angle brackets, by which the airbag system is fastened deformably to a switchboard of the motor vehicle, are connected to the generator housing. This additional deformation of the angle brackets further reduces impact. In addition, the plastic deformation is used to allow deformation at the switchboard.
Because of the arrangement of the web of the head impact element in a plane with the wall of the generator housing, a flat blast channel is formed that has virtually smooth walls. In the event of a load the upper channel wall of the head impact element is braced against the second channel wall of the generator housing.
The face-sided walls of the blast channel are formed by the legs of the head impact element and by the brackets, thus resulting in an additional common face-sided channel wall that is continuous and pulled up at the corners.
Owing to the design of the invention, a good guide of the airbag and a fast ejection of the airbag in the event of a load is achieved. Furthermore, to reduce the magnitude of head impact in the area of the switchboard, a slightly deformable blast channel is provided. To fulfill these two requirements, the invention provides that the blast channel has two pieces. These two pieces have the special advantage that even the corner regions of the blast channel are dulled. Now in the event of a load, even the corner regions can be loaded with a force and give way so that there are no longer any tension spikes.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.